There are three main bodies responsible for the agreement and implementation of legislation in the EU.

The Commission is responsible for the initiation and implementation of legislation. There are 27 Commissioners, each appointed by their country. The Commission is divided into 37 services (including Directorate Generals (DGs) and general services) and animal welfare issues fall under a variety of portfolios (such as Environment, Research, etc.).

The European Parliament has 785 Members (MEPs), who are elected by the citizens of the 27 Member States every five years.

Parliament has a budgetary role and can question the Commission on any issue. It also has restricted legislative power. It cannot initiate legislation, but it can amend or veto it in many policy areas. In certain policy areas, it can only give an opinion. Parliament has to approve the appointment of Commissioners and has a veto on the enlargement (of EU members) process.

Parliament has 20 Committees, which discuss legislative proposals from the Commission. A lead committee is designated according to the subject under discussion and a report on the proposal is drawn up by a rapporteur designated from the members of that Committee. Once the committee reports are finalised, they are voted on during the Plenary session.

The Council of Ministers directly represents the 27 Member State governments and it is the principal decision-making body. Each country has representatives on the Council, the number of votes each Member State can cast is set by the Treaties. The Treaties also define cases in which a simple majority, qualified majority or unanimity are required to pass an item. The total number of Council votes is 345. Certain issues, such as changes to the Treaty require a unanimous agreement.